Systems, methods and devices for diagnosing sleep apnea

ABSTRACT

Systems, methods and devices for diagnosing sleep apnea are provided herein. In one example, a device for detecting airway obstructions may be provided where the device may include a wearable hollow nasal tube to be positioned in an upper airway above a constriction point and an end imaging sensor coupled to the nasal tube to collect airway image data. The device further may include a controller and communication interface to communicatively link and relay airway image data to a select remote device to determine airway obstructions. In some examples, a method may be provided including receiving airway image data from a remote end imaging sensor coupled to a nasal tube disposed within an upper airway above a constriction point, and analyzing the airway image data and displaying in a sleep study report the airway image data to identify airway closures related to obstructive sleep apnea.

FIELD

The present description relates generally to systems, methods anddevices for diagnosing and monitoring sleep, sleep abnormalities, sleepapnea and related conditions, and more particularly, to systems, methodsand devices for observing airway patency during sleep.

BACKGROUND AND SUMMARY

Obstructive sleep apnea (OSA) is a disorder in which a person frequentlystops breathing during the sleep cycle as the tongue periodicallycollapses the upper airway to constrict the flow of air therein.Although the prevalence of OSA in the United States is estimated to be3-7% in men and 2-5% in women, in some populations (e.g., obese patientswith a body mass index greater than 28%) the prevalence increasesdramatically. In addition, up to 93% of women and 82% of men havingmoderate to severe OSA may go undiagnosed for many years if at all dueto diagnostic limitations of the currently known methods.

Sleep studies designed to detect and diagnose OSA often occur at a sleepstudy center using polysomnography (PSG). However, PSG involves hookinga patient up to many wires during the sleep period, which may interferewith the sleep cycle and thereby increase the difficulty of diagnosis.Portable PSG units are known and further designed to reduce PSGcomplexity but still rely on delayed physiological responses after anairway closure has occurred. Endoscopic techniques are known that areaimed at monitoring breathing and snoring during the sleep cycle.However, such techniques may still require cumbersome equipment tomonitor airflows within the upper airway and further lack a means fordetecting a sleep position, especially in a remote environment where atrained professional is not present to observe the sleep cycles.

The inventor has recognized disadvantages with the approaches above andherein discloses a wearable hollow nasal tube to be positioned in anupper airway above a constriction point that comprises an end imagingsensor coupled to the nasal tube to collect airway image data; and acontroller and communication interface to communicatively link and relaythe airway image data during sleep to a select remote device todetermine airway obstructions. In one embodiment, the device furthercomprises an inflatable balloon to anchor the nasal tube such that theend imaging sensor, which is placed at a distal end of the nasal tube,is disposed in an airway image data collection position. Thereby, thedevice may be positioned within a nasopharnyx above the constrictionpoint with the end imaging sensor angled downward relative to a noseopening, which allows for enhanced viewing of the airway. As describedherein, the device may further include one or more biophysical sensorsfor the enhanced detection of airway patency during OSA screening anddiagnosis while an air sampling port configured for monitoring airflowand performing air analysis (e.g., capnography) while visual images ofthe upper airway are collected may also be included. The device mayadvantageously further include a head positioning sensor for detecting adevice orientation relative to a head position, which allows airwaypatency to be correlated to sleep positions during sleep studies.Therefore, by placing the nasal tube and end imaging sensor above thepoint of airway constrictions, breathing patterns can be monitoredduring sleep without interfering with sleep cycles while the devicerecords and communicates with a remote computing device connected via anetwork connection. In this way, the device and methods described can beused to advantage for diagnosing OSA by directly imaging the airway,particularly in response to a sleep position, and especially when sleepactivities occur remotely.

As provided herein, in some examples, sleep studies using the discloseddevice and systems thereof may be performed in a first location whileone or more breathing patterns are remotely analyzed in a secondlocation simultaneously or subsequently, which allows for real-time orearly diagnosis of sleep abnormalities in a more convenient manner forboth the patient and healthcare professional. For example, a patient mayperform the sleep study in the comfort of their own home at night in theU.S. while observations are made and results of the sleep study areanalyzed during the day in China (or other locations), or vice versa.Furthermore, in some embodiments, the device may include a clock ortiming device, which allows recorded measurements to be time-stamped andthereby synchronized for further data analysis of sleep patterns.

The above advantages and other advantages, and features of the presentdescription will be readily apparent from the following DetailedDescription when taken alone or in connection with the accompanyingdrawings. It should be understood that the summary above is provided tointroduce in simplified form a selection of concepts that are furtherdescribed in the detailed description. It is not meant to identify keyor essential features of the claimed subject matter, the scope of whichis defined uniquely by the claims that follow the detailed description.Furthermore, the claimed subject matter is not limited toimplementations that solve any disadvantages noted above or in any partof this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages described herein will be more fully understood by readingan example of an embodiment, referred to herein as the DetailedDescription, when taken alone or with reference to the drawings, where:

FIG. 1A shows an exemplary schematic diagram of the system according tothe present disclosure;

FIGS. 1B-D show example airways to illustrate normal inhalation duringsleep and obstructed airways that represent complete and partial airwayblockages;

FIGS. 2A and B show example embodiments of the system of FIG. 1A withthe airway assessing apparatus inserted into the nasal cavity;

FIGS. 3A and B show exemplary hollow nasal imaging devices according tothe present disclosure;

FIG. 4 schematically illustrates how the head position sensor maydetermine the head position based on data collected;

FIG. 5 shows an enlarged view of a hollow nasal imaging tube withexemplary adjustable sensors whose position changes via balloondeployment;

FIGS. 6A-D show example schematic illustrations of an airway closure andmeasurement;

FIG. 7 is an example illustration showing how various data may becollected in combination with the visual images of FIG. 6 to diagnosesleep apnea;

FIG. 8 is an example flow chart illustrating operation of the airwayassessing apparatus according to the present disclosure; and

FIG. 9 is an example flow chart for diagnosing OSA based on datareceived from the airway assessing apparatus.

DETAILED DESCRIPTION

A wearable tubular airway assessing apparatus and methods fordetermining airway constriction are described that allow visual imagesof the constriction to be collected in combination with sensed airwayand head position data. In one example, the device may be configured forsending and receiving data signals, which thereby allows for real-timedata transmission and remote control of the device while a sleep studyis performed in one location and the data analyzed in a second remotelocation. Inclusion of a head positioning sensor further allows airwaypatency to be correlated with sleep positions during the sleep study forenhanced OSA diagnosis. Although the device is described in someembodiments including one or more other sensors (e.g., airflow and/orcapnography sensor) that operate in combination with the end imagesensor described, it is to be understood that in some embodiments, thedevice may comprise the wearable hollow nasal tube with an end imagingsensor to collect airway image data while one or more other sensors maybe a peripheral device (e.g., a commercially available pulse oxymeter)whose operation may be coordinated and/or synced with the airwayassessing apparatus herein. Therefore, the airway assessing apparatus ofthe present disclosure allows imaging of the upper airway during sleepin combination with collection of other sleep physiological data fordiagnosing obstructive sleep apnea (OSA). As described herein, in someembodiments, the airway assessing apparatus may comprise anasopharyngeal imaging sensor and light source, a head position sensor,an information processing center and control system, and varioussensors, such as an airflow sensor, oxygen and/or carbon dioxide sensors(e.g., capnography), an electroencephalography (EEG) sensor,electrocardiography sensor (EKG), and one or more sound-detectingdevices, etc. In particular, the nasal imaging sensor of the airwayassessing apparatus may be positioned within the nasal cavity above theoropharynx to allow visual confirmation of airway patency or obstructionfrom a collapsed tongue and uvula in OSA.

The device described is further configured for secure placement withinthe nasal cavity for long periods of time. For instance, during a sleepstudy a user may wear the tubular apparatus for up to 12 hours whiledata is collected in the manner described below. Therefore, the wirelessdevice is also designed for mobility and allows the patient a simplemeans to attend to the infrequent breaks that sometimes occur during thesleep cycle (e.g., using the restroom, getting a drink of water, etc.).As such, the device may be easily inserted into the cavity as a wearableapparatus that maintains a substantially constant view of the airwayregion throughout the entirety of the sleep study.

As a further example, the device may be positioned within the nasalcavity during the awake state to record baseline measurements of airwaydiameter and other physiological parameters. Then, the same parametersmay be subsequently recorded during the sleep state at a later time,which thereby allows for determination of one or more facts, including,but not limited to, the occurrence, frequency, and degree of airwayobstruction or OSA. In addition, inclusion of a head position sensor, insome embodiments, may enable a device orientation relative to a headposition to be determined during the sleep cycle. In this way, thedevice can record visual images of the airway diameter changes orobstruction in relationship to body posture or head position. Forpurposes of clarity, the same reference numbers are used in the drawingsherein to identify similar elements.

FIG. 1 shows an exemplary schematic diagram of OSA diagnostic system 100according to the present disclosure. As described in detail below,airway assessing apparatus 102 may include various sensors forvisualizing and detecting ventilation patterns associated with airwayobstruction. For example, in the embodiment herein described, endimaging sensor 104 may be a thermal or regular camera located at thedistal end of a tube within airway assessing apparatus 102 that is usedto visualize the upper airway from above the point of airwayconstriction. It should be appreciated that the end imaging sensor maybe positioned at the end of the tube in some embodiments, substantiallynear the end of the tube in other embodiments or any other position thatenables visualization of the upper airway from above the point of airwayconstriction. Nasal imaging sensor 104 further allows for collection ofcontinuous or intermittent video (e.g., 1 frame/second) and therebyrecords the respiratory dynamic, airway patency and anatomic changeswithin the upper airway during the cycles of sleep. In particular, theimages can be used to determine the degree and duration of upper airwayobstruction relative to the baseline profile collected when the subjectis awake. For example, imaging data may be used to identify thefrequency and duration of airway narrowing (e.g., hypopnea is diagnosedif a partial obstruction occurs for more than 10 second) or collapse(e.g., apnea is diagnosed if a substantially complete obstruction occursfor more than 10 second) which may be determined or calculated from theimages collected. In this manner, an Apnea-hypopnea Index (AHI) can befurther generated as one of the diagnostic indicators of OSA. AHI refersto the number of apnea and hypopnea episodes occurring within a timeperiod, for instance, per hour of sleep. Although traditional diagnosisof OSA using AHI routinely relies upon secondary substantial indicatorsof complete or incomplete airway obstruction, in contrast, the deviceand system described herein obtains the AHI using direct imaging of theairway. Further, as also described herein, a light source (e.g., an LEDbulb) may also be included for illuminating the upper airway to enhancethe viewing environment within the internal cavity. However, inembodiments where the end imaging sensor is a thermal imaging sensor,the light source may be optionally included.

In some examples, airway assessing apparatus 102 may include insertiontubes. For example, in the embodiment illustrated, and not as alimitation, two tubes may be provided for inserting into the nasaland/or oral cavities. In some examples, the tubes may be communicativelylinked with one or more airflow speed and capnography sensors 106, alsoreferred to as airflow sensors. These sensors may be included within thedevice for measuring or indicating an airflow, gas level and/or exchangerate during the sleep cycle or some other period. Inclusion of one ormore airflow sensors further allows correlation to the visual images fordifferentiating OSA from normal reflex responses (e.g., unintentionalswallowing, sneezing and/or coughing) during sleep. As described herein,one or more airflow sensors can be incorporated into the device thatallow airflow or CO₂ measurements through the nose, mouth and/or tracheaeither separately or simultaneously.

In some instances, occurrence of an airway constriction may depend on aparticular sleep position adopted during the sleep cycle. Therefore, inone example device, a head position sensor 108 may be embedded thereinfor indicating an orientation of the device relative to a patient headposition. For example, head position sensor 108 may be an accelerometercapable of measuring a local inertial frame relative to thegravitational field. As such, placement of the airway assessingapparatus into one or more cavities relative to a head position mayallow the position of the device relative to the gravitational field tobe determined. The head position data may be used to determine orextract a patient sleep position (e.g., lying down in the supineposition with face up) throughout the sleep cycle. The patient sleepposition data may be further synchronized and correlated with othersensor and airway blockage data. As a result AHI can be established forvarious sleep positions, e.g., supine position, left lateral position orright lateral position. Furthermore, a head movement counter to collecthead position data including a number or frequency of head movementsduring sleep may also be established in order to determine the qualityof sleep.

In some embodiments, various additional biophysical sensors 110 fordetecting EEG (electroencephalography), EKG (electrocardiography), EOG(electrooculography), EMG (electromyography) and/or tissue oxygensaturation may also be communicatively linked with the device.Therefore, in one example, the device may include an oxygen saturationsensor to collect airway data, where the airway data is relayed to aselect remote device along with the airway image data. With respect tosensor placement, the biophysical sensors may be positioned on a surfaceof the device (and/or within the device) or on a related accessory orcomponent. Inclusion of biophysical sensors may enable select autonomicreflex data to be collected and correlated to the visual images forconfirmation of the OSA diagnosis. In a further example embodiment,airway assessing apparatus 102 may also include one or more tracheasensors 112 for monitoring various conditions simultaneously from aboveand below the point of constriction. For example, trachea sensor 112 maybe a sound-detecting device such as a microphone, stethoscope or Dopplersound device.

In another example embodiment, trachea sensor 112 may be an oxygensensor or a nitrogen sensor for monitoring oxygen and/or nitrogen levelsthat exist naturally in the trachea. In yet another example, the tracheasensor may be a magnetic sensor such as a permanent magnet orelectromagnet that is configured to generate a magnetic field within thetrachea. As a non-limiting example, trachea sensors 112 and air samplingtube 220 (shown in FIGS. 2 and 3), which may be disposed at any locationon the device, may be included to sample the air and airflow within thenasal and/or oral cavity. Use of the trachea sensor and air-samplingtube may provide additional gas analysis, for example, via capnographyor mass spectrometry, etc.

Referring back to FIG. 1, controller 120 may include processor 122,memory unit 124, and a communication interface 126. Processor 122 andcommunication interface 126 may be linked by a bus to memory 124.Controller 120 may also be configured to communicate with remotecomputing device 130 via communication interface 126. In someembodiments, memory 124 may include both non-volatile and volatilememory, and programs or algorithms may be stored in non-volatile memoryand executed by the processor using portions of volatile memory toaccomplish the operations described herein. Controller 120 may alsoinclude a programmable 24-hour clock and timer device, which allowssynchronization of data collection processes and, in some embodiments,may further enable the collected data to be time stamped for futureanalysis.

Airway assessing apparatus 102 may be configured to communicate with aremote computing device 130. As such, controller 120 may further includea transmitter for sending and receiving wireless signals. For example,data stored locally within the device may be uploaded to a remotecomputing device 130 through one or more network connections (e.g., viathe internet through a WiFi connection) for review by a trainedprofessional at a provider's or doctor's office and/or sleep studycenter. Thereby, the device according to the present disclosure mayenable, in some embodiments, data to be uploaded remotely in real-timeor at the end of the study. Alternatively, or additionally, a port, suchas a data input/output port, may be included for directly connecting thedevice to a remote computing device (e.g., a computer in a doctor'soffice or other user device), which may allow stored data to bedownloaded directly to the computing device at the end of a study.

In some examples, remotely recorded data stored within memory unit 124may be viewed manually by one or more trained professionals and/orautomatically analyzed by a data processor. For instance, OSA analyticaltoolbox 132 may be present on remote computing device 130 for analyzingone or more sensed data patterns in order to diagnose obstructive sleepapnea or degree of airway constriction during the sleep cycle. Forsimplicity, analytical toolbox 132 is shown comprising a ventilationpattern analyzer 134 for analyzing and comparing one or more datapatterns associated with obstructive sleep apnea; image pattern analyzer136 for assessing an obstruction or degree of obstruction while alsodifferentiating the closure from other reflex actions that occur withinthe upper airway; biophysical pattern analyzer 138 for analyzing one ormore biophysical data patterns; and an OSA report generator 140 forgenerating a formatted printout of diagnostic results to facilitatephysician diagnosis.

Although OSA analytical toolbox 132 is shown including pattern analyzer134, image pattern analyzer 136, biophysical pattern analyzer 138, andreport generator 140, these tools are shown for example and arenon-limiting. Other analytical routines are also possible. As anillustration, analytical toolbox 132 may comprise tools for diagnosingOSA based on collected data. For example, one or more of the toolstherein may be used to calculate AHI, or the Apnea-Hypopnea index, whichrefers to the number of episodes of apnea and hypopnea occurring perhour. As noted above, Hypopnea occurs when a partial obstruction lastsfor 10 seconds or longer whereas Apnea occurs when a substantiallycomplete obstruction lasts for more than 10 seconds. Moreover, the AHIscale may be used to diagnose OSA based on the number of episodesdetected. As one example, mild OSA is diagnosed upon detecting 5-15episodes per hour; moderate OSA is diagnosed upon detecting 15-30episodes per hour; and severe OSA is diagnosed upon detecting over 30episodes per hour. Additionally or alternatively, such data may becombined with information from other sensors to arrive at an OSAdiagnosis. For instance, head movement or position data collected byhead position sensor 108 may be used in combination with images of theairway to further determine sleep quality. As another example, adecreased saturation of peripheral oxygen (SPO₂), or oxygen saturationmay also be measured (e.g., by pulse oximetry) along with EEG or EKGchanges and correlated to one or more of a data pattern or sleepposition. In this way, the device described may be used for diagnosingOSA when determining sleep quality.

FIGS. 1B and 1C show example airways to illustrate how a blocked passagemay occur due to tongue collapse during the sleep cycle. As illustrated,the figures show an example inhalation pattern of an open airway and anobstructed airway along with various anatomical features for reference.For example, FIG. 1B shows that during normal inhalation, nasal airflow150 and oral airflow 152 enter the nasal and oral cavities,respectively. Then, because the airway is open and therefore not blockedby a collapsed tongue, the two airflows may converge into a singleairflow that is further directed into the trachea and to the lungs (notshown) of an individual. Conversely, FIG. 1C shows that the airwaybecomes obstructed when the tongue collapses to push the soft palate(including the uvula) and epiglottis toward the back of the airway. Inresponse to the obstruction event, the nasal and oral airflows may beblocked as indicated by the X-capped lines shown at 160 and 162,respectively.

For clarity, FIG. 1D shows a partially obstructed airway wherein airflowturbulence occurs at the point of constriction. As shown, in oneexample, nasal airflow 170 may occur while oral airflow 172 issimultaneously blocked. However, other examples relative airflowconfigurations are possible. Therefore, both airflows may also bepartially open or, alternatively, air may flow through the oral cavitywhile airflow through the nasal cavity is simultaneously blocked in someinstances. Because the airway is partially obstructed, a turbulentairflow 174 may occur wherein the airflow through the point ofconstriction is chaotic and irregular. In some instances, turbulentairflow 174 may result in the unpleasant sounds of snoring as vibrationswithin the respiratory structures occur that are due to air movementthrough the partially obstructed airway during breathing while sleeping.As a result, in some instances, airflow 176 may be reduced compared tonasal airflow 170 as shown by the dashed lines therein. In this manner,one or more airways may become blocked that are detectable using themethods according to the present disclosure.

FIGS. 2A and 2B show example embodiments of OSA diagnostic system 100 inaccordance with the present disclosure. For example, FIG. 2A showsairway assessing apparatus 102A with nasal tube 202A inserted into nasalcavity 204. Nasal tube 202A may be a flexible hollow tube adapted forinsertion into the nasal cavity. In some examples, nasal tube 202A mayinclude a soft, bendable beak-like tip 203 or other configuration thatallows for downward deflection and easier insertion and placement of thedevice within the cavity above constriction point 206. In the firstembodiment shown, airway assessing apparatus 102A includes nose stopper210 along with mesh 212 that enables air to pass through the hollowdevice and into the airway. The device may also include pilot balloon230 with air injection port 232 (or valve) that is used for inflatingballoon 250 through inflation opening 252. In the embodiment shown,inflatable balloon 250 may be included along with the nose stopper toanchor the device in place during the sleep study period. In this way,inflating the balloon allows for increased contact between the balloonand nasal cavity, which thereby acts to anchor the device and preventinward or outward movement of the device during the sleep study.Therefore, placement of the device is stabilized, which allows for amore consistent imaging environment and enhanced clinical utilityaccording to the methods described herein. Moreover, the seal betweenballoon 250, which may be one or more balloons in some embodiments, andthe nasal cavity may further create a tunnel through the hollow devicethat acts to direct the airflow there through. As such, airflow throughthe device is optimized to enable more sensitive diagnostic measurementsduring the sleep study.

In the example illustrated, nasal tube 202A is a tube with 70 to 90degree bend at the distal end for viewing the airway when placed aboveconstriction point 206. As such, the tube shape shown, which isnon-limiting, allows for an enhanced view of the uvula, soft palate, andairway constriction via end imaging sensor 104. Herein, end imagingsensor 104 is a camera for simplicity. However, in other embodiments,end imaging sensor may be a thermal imaging device. Therefore, endimaging sensor 104 is a camera located at the distal end of nasal tube202A. Although the embodiments herein describe a curved device or adevice with a bend for enhanced viewing of an airway constriction, ithas been contemplated that end imaging sensor 104 may further includecomponents for adjusting a position relative to the nasal tube. However,for simplicity, end imaging sensor 104 is herein described with anorientation giving a clear view of constriction point 206 when placedinto the nasopharynx as shown. For instance, when the distal end ofnasal tube 202A is positioned within the nasopharynx as shown in FIG.2A, the tube end forms an angle ranging from 70 to 90 degrees withrespect to nose stopper 210. Therefore, the end imaging sensor is angleddownward relative to a nose opening to view an airway, and the angle ofplacement is generally described as being near, but less than 90 degreesfor simplicity, which allows for optimal viewing of the airway and anyconstrictions occurring therein.

FIG. 2B shows a second embodiment of airway assessing apparatus 102Bthat also includes nasal tube 202B with a soft, bendable end and aflexible beak-like tip 203 for easier insertion and downward deflectionto increase the ease of placement within nasal cavity 204 aboveconstriction point 206. In one embodiment, beak-like tip 203 isintegrated into the bendable nasal tube and comprises a piece of plastichaving the contour of a beak. Thereby, the beak-like tip and nasal tubemay form a single, continuous structure. However, this is non-limitingand in other embodiments, the beak-like tip, which is soft and flexible,may also comprise a separate tip configured for addition to the end ofthe nasal tube and/or may be made of other materials (e.g., rubber) solong as the material is insertable into the body for long periods oftime. As noted above, the tip allows for easier and nontraumaticinsertion of the tubular airway assessing apparatus into the nasalcavity, since traumatic insertion (and bleeding) may interfere withsensor operation, and in some instances compromise image sensor clarity.For example, during insertion into the nasal cavity, the tip may contactthe back of the cavity just above the nasopharynx. In response, thebeak-like tip may flex and slide down the nasal cavity to create thedownward deflection that advantageously places end imaging sensor 104above airway constriction 206. In addition, nasal tube 202B, is a hollowtube with a diameter smaller than a nostril opening and length (e.g.,less than the distance between the nose and ear) that allows placementwithin the nasal cavity above the point of constriction (e.g., withinthe nasopharynx before the oropharynx). As provided in this example, thedevice may allow for spontaneous nose breathing while not interruptingthe sleep cycle. As further shown, nasal tube 202B is connected to nosestopper 210, which divides nasal tube 202B into first and secondportions and is included to prevent the device from being inserted toofar into the nasal cavity, which may compromise the diagnostic processby allowing the tube to bypass the constriction point and thereby tobecome a treatment device. Therefore, nose stopper 210 stabilizes theposition of the device relative to the nasal cavity and thereby offers aconsistent environment for viewing the airway passage, especially overlong periods of time (e.g., 4-10 hours) associated with a sleepduration. In some embodiments, air sampling tube 220 that may bepositioned in front of the mouth 222 may be coupled to nasal tube 202Band nose stopper 210. However, this is non-limiting and the tube may beconnected at other locations along nasal tube 202B.

Air sampling tube 220 is used to indicate mouth breathing. In oneexample embodiment, air sampling tube 220 may include a microphone orother audio device. In some examples, the microphone may be positionedin front of the neck to indicate airflows. As such, in some instances,the length of air sampling tube 220 may be substantially long so as toreach the neck region during a sleep study. However, the length of airsampling tube 220 is non-limiting, and in other examples, the airsampling tube may be an air sampling port for gas analysis, whereairflow is sampled at a constant rate for capnography analysis (e.g., aclosed tube sticking out from air sampling tube 220). Inclusion of theair sampling tube 220 allows false positive results to be substantiallyeliminated since some people are total mouth breathers that exhibit noairflow through the nasal cavity. For these people, airflow from themouth or microphone may indicate breathing whereas the images collectedmay show an airway collapse, which indicates a false positive resultthat is not considered as an episode of apnea. Moreover, false negativesmay occur when no flow is detected via the mouth, nose and tracheamicrophone, but where images show an open airway, for example, as occursin central sleep apnea, which is a brain condition that occurs due to aninstability of the body's feedback mechanism to generate neuralrespiration signals.

In FIGS. 2A and 2B each airway assessing apparatus is connected tonetwork 240. As such, the portable device may be configured to connectto network 240 while enabling communications with a plurality of remotecomputing devices 242, which may be configured to automatically analyzedata received therefrom. Computing device 242 may be located remotely toa location where a sleep study is performed. Connections between eachairway assessing apparatus and computing device 242 therefore allows formonitoring and controlling the device remotely. For example, informationfrom end imaging sensor 104 (e.g., visual images) may be sent tocomputing device 242 during a sleep study. In turn, a user may alsoreceive instructions from network 240. In this way, the sleep study maybe monitored, controlled and/or supervised remotely. Communicationsbetween the airway assessing apparatus and network may be useful whenthe device is used in a sleep study center or home environment, or whenthe study is performed by less-trained personnel. As such, the sleepstudy may be performed at one location and supervised by a person usingcomputing device 242 at the same location. Or, a user may use computingdevice 242 to remotely operate and control the airway assessingapparatus disclosed. For example, data collection may be initiated by adoctor in one location while the study is performed at another location.Furthermore, the airway assessing apparatus and a computing device maybe connected via a network through a wire or wireless connections.

FIGS. 3A and 3B show exemplary hollow nasal imaging devices according tothe present disclosure. In FIG. 3A, airway assessing apparatus 102A thatis described with respect to FIG. 2A is shown in more detail. As notedalready, airway assessing apparatus 102A is a first embodiment of hollownasopharyngeal imaging device 300A. As described already, airwayassessing apparatus 102A includes hollow nasal tube 202A that is shownwith a 70 to 90 degree bend at the distal end of the flexible tubing.Thereby, the shape of the device allows for enhanced views of the airwayupon placement into the nasal cavity. Beak-like tip 203 is also includedand further allows for easier placement of the device within thenasopharynx in the manner already described. End imaging sensor 104 islocated at the distal end such that images may be collected of theairway during a sleep study. Nasal tube 202A is further connected tonose stopper 210, which is included to prevent the device from beinginserted too far into the nasal cavity. Therefore, nose stopper 210stabilizes the position of the device relative to the nasal cavity andthereby offers a consistent environment for viewing the airway passage,especially over long periods of time (e.g., 4-10 hours) associated witha sleep duration. In the embodiment shown, nose stopper 210 includesmesh 212 that allows for an airflow therethrough.

As described above, airway assessing apparatus 102A also includes pilotballoon 230 with air injection port 232 (e.g., a valve) that is used forinflating balloon 250 through inflation opening 252. In the embodimentshown, balloon 250 may be included to anchor the device in place alongwith the nose stopper during the sleep study period. For example, theballoon may be inflated to allow for increased contact between theballoon and nasal cavity, which thereby acts to anchor the device andprevent inward or outward movement of the device during the sleep study.In this way, the inflatable balloon is included to anchor the nasal tubesuch that the end imaging sensor is disposed in an airway image datacollection position. As such, placement of the device is stabilized,which allows for a more consistent imaging environment and enhancedclinical utility according to the methods described herein. Moreover,the seal between balloon 250, which may be one or more balloons in someembodiments, and the nasal cavity may further create a tunnel throughthe hollow device that acts to direct the airflow therethrough.Therefore, airflow through the device is optimized to enable moresensitive diagnostic measurements during the sleep study. In addition,balloon 250, may be used to adjust the position of one or more sensorsthrough balloon deployment. Thereby, as described in more detail below,a sensor position may be adjusted by inflating a balloon located beneaththe sensor in response to an output below a threshold in order to adjustthe relative height of one or more sensors and thereby increase thesurface contact area between the sensor and a wall of the nasal cavity.Dashed lines are included to indicate a surface within the hollow tubewherein air from injection port 232 can pass through to reach one ormore balloons within the device.

With respect to the structure of airway assessing apparatus 102B, FIG.3B shows an exemplary hollow nasopharyngeal imaging device 300Baccording to the second embodiment of the present disclosure. Hollownasopharyngeal imaging device 300 includes nasal tube 202B connected tonose stopper 210 and further coupled to second air sampling tube 220.Upon placement of the device into a cavity, bi-directional airflow mayoccur. For example, during exhalation when no airway closure occurs, airmay flow from trachea 226 into the nasal cavity and through nasal tube202B. Additionally, or alternatively, air may also flow from trachea 226into the oral cavity and through mouth 222. In the same manner, duringinhalation external air may be conducted into the body by entering theproximal end of nasal tube 202B and further branching into two airflowsthat travel through nasal tube 202B and second air sampling tube 220,which in some instances may be a closed port coupled to the airflowthrough airway assessing apparatus 102B as indicated by the dashed airsampling tube 220 in FIG. 3B, and wherein airflow may be sampled at aconstant rate for capnography analysis. Alternatively, when an airway isconstricted, one or more of the airflows through the device may bereduced or substantially eliminated. Although the description hereinplaces a nasal tube into the nasal cavity and the second air samplingtube in front of the oral cavity, in some embodiments, one or the otherof the two tubes may be placed alternatively to record data using one ormore other data sensors. For example, air sampling tube 220 mayalternatively include a microphone sensor that is placed in front of thetrachea to monitor an airflow therethrough. Further still, in otherexamples, a device may include a single tube for visually monitoring anairway from above a point of constriction.

Returning again to FIG. 3B, in the example illustrated, nasal tube 202Bis a tube that is curved relative to the longitudinal axis of the deviceto enable placement of the device relative to constriction point 206. Assuch, tube curvature allows an enhanced view of the uvula and softpalate in addition to airway constriction via end imaging sensor 104,which in one embodiment is a camera located at the distal end of nasaltube 202B. Although the device is described as being curved relative tothe longitudinal axis, the amount of curvature may vary duringoperation. For instance, when the distal end of nasal tube 202B ispositioned within the nasopharynx as shown in FIG. 2B, the tube endforms an angle ranging from 70 to 90 degrees with respect to nosestopper 210. Therefore, the angle of placement is generally described asbeing near, but less than 90 degrees for simplicity, which allows foroptimal viewing of the airway and any constrictions occurring therein.

As noted above, in some embodiments, the device may further includenasopharyngeal light source 310 near end imaging sensor 104 that allowsfor illuminating the upper airway and increased viewing capabilitiestherein. As one example, nasopharyngeal light source 310 may be anintermittent flash light or a constant LED light with a small area(e.g., less than 1 mm²) having low energy consumption and highdurability to accommodate the nature of a lengthy sleep study. However,in other embodiments, nasopharyngeal light source 310 may be athermographic or infrared camera for forming an image using heatprofiles within the airway.

End imaging sensor 104 may be configured for continuous or intermittentvideo (e.g., 1 frame/second) recording during sleep cycles. As such,dynamic images of the anatomic changes of the upper airway can be viewedto assess an obstruction or degree of obstruction compared to a baselineprofile collected when the subject is awake. Because each imagerecording is time stamped, the frequency and duration of airwaynarrowing or collapse may also be calculated from the images collected.For example, imaging data may be used to determine the airway opening is50% narrowed for 10 seconds or more at a frequency of 20 times per hour,which is further used to calculate an AHI consistent with moderate OSA.Alternatively, as another example, imaging data may be used to determinethe airway is 100% obstructed for 10 seconds or more with a frequency of30 times per hour, which produces an AHI consistent with severe OSA.Therefore, according to the present disclosure, the airway assessingapparatus described may allow AHI calculation from direct imaging of theairway.

Airflow speed and composition sensors shown schematically at 106 mayalso be included within the device. Inclusion of airflow sensors allowsfor the airflow through the nose, mouth and/or trachea to be monitoredseparately or simultaneously in some instances. An airflow indicator maydetermine airflow from the mouth to generate airflow data. Thereby, datafrom one or more airflow sensors may provide confirmation of the visualimages collected and further allow differentiation of OSA from normalphysiological reflexes that occur (e.g., swallowing, sneezing, andcoughing during sleep). For example, during airway obstruction, theairflow through both the nasal cavity and oral cavity (or trachea) maycease whereas during a reflex response, air may continue to flow throughthe oral cavity and trachea. Alternatively or additionally, in someinstances, airflow sensor 106 may be one or more of an O₂ or CO₂ sensor(e.g., capnography) for determining a gas level or exchange rate withinan airway based on the data collected.

Biophysical sensors are schematically depicted at 110 and includevarious sensors to detect EEG, EKG, EOG, EMG, and tissue oxygensaturation. Biophysical sensors 110 may be placed at the surface of thenasal tube to allow further confirmation of OSA in the manner describedin detail below. Because the biophysical sensors 110 may in someinstances depend on contacting a cavity wall for signal detection, theposition of one or more sensors may be adjusted relative to the surfaceof the device (e.g., by increasing or decreasing a sensor height) bydeploying a balloon underneath the sensor to adjust the sensor positionand thereby increase a sensor surface contact area. In this way, thesignal sensitivity may also be increased for increased detection ofventilation patterns based on the acquired signal. Although balloons maybe included to enhance a sensor surface contact in one instance, inanother instance, one or more balloons may be included to anchor thedevice in place along with the nose stopper during the sleep studyperiod. As such, pumping air into a balloon allows for increased contactbetween the balloon and nasal cavity, which thereby acts to anchor thedevice while preventing inward or outward movement of the device duringthe study. As such, placement of the device is stabilized, whichadvantageously allows for a more consistent imaging environment andenhanced clinical utility. Moreover, the seal between one or moreballoons and the nasal cavity acts to create a tunnel through the devicethat directs the airflow therethrough. Therefore, airflow through thedevice may be optimized, which enables more sensitive diagnosticmeasurements during the sleep study.

As noted above, trachea sensors 112 may be included within second airsampling tube 220 that comprise one or more sensors for monitoringvarious conditions near the trachea below the point of constriction. Forexample, the trachea sensor may be a sound-detecting device comprisingat least one of a microphone, stethoscope or Doppler device designed todetect one or more breathing patterns and anatomical changes associatedwith OSA. In an alternate embodiment, trachea sensors 112 mayadditionally or alternatively be included within the nasal tube andtherefore detect breathing patterns and anatomical changes within nasalcavity 204. Although trachea sensor 112 is shown placed at the end ofair sampling tube 220, this placement is non-limiting and the sensorsmay be located at any position along the device such that diagnosticmeasurements are enabled.

With respect to the devices shown in FIGS. 3A and 3B, collected sensordata may be relayed and processed by controller 120. Controller 120 maybe a microcomputer, including microprocessor unit 122, input/outputports 330, an electronic storage medium for executable programs andcalibration values shown as read only memory (ROM) chip 124 in thisparticular example, and a data bus. Storage medium read-only memory 124can be programmed with computer readable data representing instructionsexecutable by processor 122 for performing the methods described belowas well as other variants that are anticipated but not specificallylisted. Controller 120 may receive various signals from sensors coupledto an airway assessing apparatus, in addition to those previouslydiscussed.

In addition to the sensors above, a head position sensor 108 may beembedded within nose stopper 210 for determining a head position duringthe sleep cycle. Nose stopper 210 may be located at the proximal end ofthe airway assessing apparatus and therefore prevent the device fromsliding inward or outward during the sleep study period. As such, nosestopper 210 may have a larger diameter and a larger size compared to anostril coupled to nasal cavity 204, which generally varies according toage, gender, and race. Placement of the device may be externally securedby adhering a piece of tape across the device to the patient's skin.Alternatively, in some examples, for example, FIG. 2A, the airwayassessing apparatus may further include a distal balloon that isdeployable to anchor the device and thereby prevent inward or outwardmovement relative to the cavity while also preventing accidentaldislodge from sneezing or coughing. Although the shape of nose stopper210 is shown cylindrical for simplicity, other shapes have beenconsidered and are possible. In one example embodiment, head positionsensor 108 is a three-axis accelerometer but this is non-limiting andthe head position sensor may also be a gyroscope or sensor for detectingvarious motions therein. Since head position sensor 108 provides anindication of device orientation relative to a patient head position,the head position during the sleep cycle may be extracted from datacollected by end imaging sensor 104 based on the relative orientation ofairway assessing apparatus 102 with respect to the patient. Furthermore,since a head position during sleep can be time stamped, recorded andcorrelated to airway narrowing or collapse, the data may be used todetermine a sleep position during the duration of the sleep cycle. Forexample, when a patient sleeps in a left lateral position at 90 degreesfrom the supine position (e.g., on their left side), said patient mayexperience 50% narrowing for 10 seconds at a frequency of threetimes/hr. Alternatively, in the supine position (e.g., asleep flat ontheir back facing upward), the same patient may experience 50% narrowingfor 10 seconds at an increased frequency of 20 times/hr. As such, headposition sensor 108 may be used for determining the head position duringsleep and thereby to diagnose OSA from the data collected. In someembodiments, nose stopper 210 may include alignment mark 320 foraligning the airway assessing apparatus 102 relative to a head positionat the outset of a sleep study. Therefore, the method according to thepresent disclosure allows for a positional AHI to be determined. Forinstance, because some people may snore more or experience an increasednumber of OSA episodes in a particular sleep position, an AHI based onthe various sleep positions (e.g., left AHI , right AHI , or supine AHI) as well as the frequency of head movement, which are both factors insleep quality, can be determined to further direct treatment.

With respect to head position detection, FIG. 4 schematicallyillustrates how head position sensor 108 may differentiate between twohead positions based on a relative sensor alignment compared to a fixedreference frame. Therein, Cartesian coordinate frame 402 (e.g.,comprising x, y, and z axes) is generally shown along with a unit vector(ũ) oriented relative to the fixed coordinate frame. For example, in oneembodiment, the y-axis of the Cartesian coordinate frame 402 mayrepresent a gravitational field while ũ represents a vector associatedwith an accelerometer reference axis.

For illustrative purposes, FIG. 4 shows a schematic diagram of a sleepposition from above a body axis, that is, looking down the longitudinalaxis of the body from above. For example, at 404, the head position isin the supine sleep position with the body facing upward. Alternatively,at 406, the head is in a left lateral position (e.g., asleep on the leftside). With such position data, the angle between the two identifiedsleep positions may be 90 degrees or another predetermined angle, whichalso corresponds to an angular displacement that can be measured by headposition sensor 108. The two different sleep positions may producedifferent physiological sleep responses in the manner already described,which can also be detected by the methods described herein and used todiagnose OSA from the data collected. Although the angular displacementbetween supine position 404 and left lateral position 406 is shown as 90degrees for simplicity, in general head position sensor 108 may detectany angular displacement and relative orientation (e.g., from movementin three dimensions instead of two dimensions).

Turning now to FIG. 5, an enlarged view of nasal tube 202A is shown tofurther describe how a sensor position may be adjusted via balloondeployment. For illustrative purposes, two example contact-sensitivesensors are shown at 502 and 504. As described above, these sensors mayrepresent EEG or EKG sensors that are located on the outside surface ofnasal tube 202A. For simplicity, reference sensor 502 is shown flushwith the tube surface whereas the position of adjustable sensor 504 ischanged by deploying balloon 506 to adjust the position of the sensorvia movement orthogonal to the tube surface. Connections between eachsensor to controller 120 are shown schematically. With regard toinflation of the balloon, in one embodiment, a pilot balloon thatincludes an air injection port and valve may be included within thedevice for inflating one or more balloons therein. A sensor position maythus be adjusted by inflating a balloon located beneath the sensor inresponse to an output below a threshold in order to adjust the relativeheight 508 identified as ΔH to increase the surface contact area betweenthe sensor and for instance, a wall of the nasal cavity. Although FIG. 5shows a balloon that is used for changing the position of a sensor, oneor more other balloons may alternatively or additionally be included forstabilizing the position of the device within the nasal cavity. Thereby,the airway assessing apparatus may be anchored into place to allow forenhanced observations during the sleep study. As noted above, one ormore balloons may also seal or plug an airway so substantially all ofthe airflow is directed through the device. As such, the one or moreballoons may stop air leaks around the tube and further create atunneling effect that increases diagnostic accuracy and measurementsensitivity. Balloon inflation may therefore occur manually at theinitial calibration stage in an awake patient, for instance, by atrained healthcare professional, or in some instances, by the patientwho may also adjust the device position via rotation and/or furtherinsertion and withdrawal. Although manual balloon inflation adjustmentsare described herein, in some embodiments, balloon pressure may beadjusted automatically based on a sensor detection level that fallsbelow a pre-set or specified threshold.

Because the device and methods herein enable visual detection of OSA byobserving airway obstructions from above the constriction point, FIGS.6A-D show example illustrations of an airway obstruction in variousdegrees of closure during sleep. These examples are provided asillustrative examples and are not intended to be limiting in any way. InFIG. 6A, the open airway is shown surrounded by the pharynx and softpalate/uvula. The epiglottis is also shown and labeled accordingly. Asdescribed in detail above, as the tongue collapses, it moves in relationto the airway and thereby acts to constrict the flow of air therein. Forexample, in FIG. 6B, the airway is partially obstructed as the tongue(not visible) pushes against the soft palate and uvula (and epiglottis)in the manner already described with respect to FIGS. 1B and 1C. Then,in FIG. 6C, the tongue substantially fully collapses and thereby blocksthe flow of air within the constricted airway. Finally, in FIG. 6D, asthe tongue relaxes and slowly releases pressure within the oral cavity,the substantially blocked airway begins to subside in a manner thatallows air to begin flowing again. As the obstruction subsides, theairway is thus re-established and the normal breathing patternre-emerges during the sleep cycle. In this way, visual images of anairway closure episode can be collected and analyzed automatically alongwith other ancillary data to determine an obstruction or degree ofobstruction throughout the sleep study period.

Because airway assessing apparatus 102 comprises various additionalsensors for monitoring and detection, the visual images collected may insome instances be correlated and/or confirmed by other physiologicalchanges following an airway obstruction. For this reason, FIG. 7 showsan example illustration of various other data that may be collected incombination with the visual images shown in FIGS. 6A-D. Therein, variousexample sensor responses are also shown as a function of time where timeincreases from left to right. The degrees of obstruction or closure fromFIGS. 6A-D are further identified by dashed vertical lines. For example,the first vertical line labeled t₀ signifies the start of the study.Then, as the study proceeds, onset of an airway constriction occurs att₁ (e.g., clock time of 23:30:20 or timer setting of 2:20:10 whereasdata collection began at 21:10:10) that signifies the airway beingpartially obstructed from collapse of the tongue. At t₂ (e.g., 23:30:30or 2:20:20), the airway is substantially constricted and physiologicalresponses begin to manifest due to a reduction in the amount of oxygenavailable. The constriction lasts until time point, t₃ (23:30:45 or2:20:35), at which point the collapsed tongue is removed from the airwayand therefore no longer blocks the airflow passage. In response to theremoval of the constriction, the physiological conditions begin toreturn to their substantially normal levels as the body recovers fromthe airway obstruction. In response to the data collected, a healthcareprofessional or analytical program may analyze the data in order toidentify an apnea episode (e.g., a closure that lasts 15 seconds)occurring when the patient sleeps in the supine position. In the exampleshown, the apnea episode is further accompanied by a cessation ofairflow, severe oxygen desaturation, bradycardia and different brainwaves compared to a reference curve (not shown) collected prior to thesleep study. Furthermore, although not shown explicitly in FIG. 7, datarepresenting a count of the accumulated head movements may also becollected and used to identify the overall quality of sleep.

As shown in the example data of FIG. 7, visually observing an airwayfrom above a point of constriction offers advantages compared tophysiological and systemic changes that result from the airwayconstriction. For example, visual imaging data can identify an airwayclosure in real-time with substantially no lag time relative to theclosure. In contrast, the data of FIG. 7 show that various additionaldata sensors may record a profile change after a timelag relative to theonset of constriction at t₁ and full constriction at t₂. As such,inclusion of these sensors provides confirmation of an OSA diagnosisbased on the visual images. In addition, because sensed data patternsbefore t₁ are regular, implementation of analytical tools to detectsubtle changes (e.g., reduction of amplitude or average value changes)and correlation of the results with visual images can be performedautomatically in some instances. Furthermore, with the device accordingto the present disclosure, such analytical activities can occur remotelyat one location while a sleep study is performed at another location.

With respect to the sensor data of FIG. 7, in the top plot, the airwayimages of FIGS. 6A-D are shown. Then, in the second plot, an exampleschematic of head position is provided. Such a pattern may be collected,for instance, by head position sensor 108. For simplicity, the angulardata shown represent a head position relative to the left lateralposition of FIG. 4. Therefore, 0 degrees at 702 occurs while the patientsleeps in the left lateral position, but an angle of 90 degrees shown at704 occurs when the patient is asleep on their back in the supineposition. It follows that an angle of 180 degrees may therefore occurwhen the patient sleeps in the right lateral position. For simplicity,in the example shown, a change in sleep position occurs along with therecorded episode of apnea. However, airway obstructions may occur formany reasons and the head position shown is provided simply for example.

The third plot in FIG. 7 shows an airflow pattern. Such a pattern may becollected, for instance, by airflow sensor 106 located within nasal tube202B. Therein, prior to t₁, the airflow data undulate with largeramplitudes in response to inhalation and exhalation events during thebreathing cycle. Then, between t₁ and t₂ when the patient changessleeping position from left lateral to supine, an airway constrictionoccurs that produces a reduction in airflow. In response to theconstriction, the amplitude of the undulating data begins to decrease,which signifies less airflow within the upper airway. At t₂, theamplitude is substantially zero due to the blocked airway. The durationof time between t₂ and t₃ may serve as a basis for assigning AHI andtherefore diagnosing OSA.

In response to the blocked airway, the O₂ saturation, which is arelative measure of the amount of oxygen dissolved in a medium such as abody tissue may also provide a measure of airway closure. For example,in one embodiment, sensor 110 may measure O₂ saturation. However, thisphysiological response may exhibit a timelag compared to the onset offull blockage at t₂. For example, at 710, an O₂ sensor response maystill be decreasing while the airflow response (and visual imaging)indicates a substantially full closure. Then, the oxygen saturation maydecrease with a timelag to a lower plateau indicating closure at 712.The resulting timelag may lead to reduced sensitivities with respect toOSA diagnosis. For these reasons, the system and methods according tothe present disclosure include such sensors for correlating the datapatterns to the visual images obtained and further confirming adiagnosis. At t₃, once the blockage is removed, the oxygen levels beginto increase as the airflow is re-established within the upper airway.

In one embodiment, sensor 110 on the surface of the device mayadditionally or alternatively detect EEG or ECG within a cavity.However, in some instances, pattern changes (e.g., at 720) may bedelayed relative to the occurrence of an airway closure, which mayinstead be used to support or establish the diagnosis according to themethods herein. In another embodiment, trachea sensor 112 may be anauscultatory sensor such as a microphone, stethoscope, or Doppler sounddevice for recording sounds within an airway associated with the heartor lungs and thereby provide a measure of arterial pressure. The bloodpressure thereby increases in response to the airway closure andprovides additional support for OSA diagnosis. In this way, asound-detecting device may be used to indicate an airflow during thesleep cycle.

In view of the above, in one example embodiment, the device may collectvisual images of an airway obstruction in combination with airflowinformation in relation to a head position during the sleep cycle. Thedata collected may be transmitted wirelessly or downloaded manually(e.g., via a wire inserted into a port) to a remote computing device andfurther analyzed to establish an OSA diagnosis. Furthermore, because thedevice includes a control system, sensor activation may be controlledremotely and one or more data patterns transmitted wirelessly forreal-time analysis as the airway data is collected, which allows forexpedient OSA diagnosis.

FIG. 8 shows an example method by which airway assessing apparatus 102may operate remotely. Specifically, FIG. 8 shows an example flow chartillustrating method 800 for controlling the device during a sleep study.As described already, the device may generate data in one location(e.g., in a home environment or sleep study center) while analysisoccurs in a second location (e.g., at a doctor's office or in a secondlocation within the sleep study center).

As described already, the method includes placement of an airwayassessing apparatus in an upper airway with end imaging sensor 104located above and in full view of a constriction point. For example,nasal tube 202B may be inserted into nasal cavity 204 until furtherinsertion of the device is blocked by nose stopper 210. Then, becausenasal tube 202B is curved relative to the longitudinal axis of the tube,end imaging sensor 104 may have a clear view of the oral cavity,including the nasopharynx, uvula and soft palate. Additionally, secondair sampling tube 220 may be positioned in front of the oral cavity andthereby measure an airflow from the mouth.

At 804, method 800 includes adjusting one or more sensor positions toincrease a surface contact area. For example, in one embodiment, aballoon may be inflated manually to adjust the position of a sensor(e.g., an EEG sensor) in a direction orthogonal to the tube surfacebased on a low but detectable signal that results from a low contactsurface area. After adjustment of the one or more sensors, at 806 abaseline measurement of the imaging and biophysical sensors may berecorded during the awake state and synchronized with the 24-hour clock.Then, at 808, data collection by one or more sensors may commence at bedtime along with the timer, which begins the sleep study. For example, inone embodiment, a timer including a start time and end time may be setwithin the device that controls the duration of the study. Furthermore,at 810, one or more sensors may be turned on and continuously orintermittently collecting data for the duration of the study, which istypically 4-10 hours in many cases. As one example, a study period maycommence at 11:00 PM and proceed until 6:00 AM the next morning.Therefore, at 11:00 PM, nasopharyngeal light source 310 may be turned onwhile end imaging sensor 104 begins collecting data at a predeterminedrate. Additional sensors, for example, airflow sensors 106 may also beactivated at the start of the sleep study and therefore collect variousdata during the course of the study. The study may occur at home or in asleep study center while a trained professional monitors the patientand/or data throughout the course of the study. Alternatively, to beginthe study, the patient may push a start button on the device upon goingto bed that activates one or more device sensors that continuously orintermittently record data for 4-10 hours while the patient is in thesleep state. In yet another alternative, a trained professional mayremotely activate one or more sensors within the device after thepatient has turned the airway assessing apparatus on.

At 812, the recorded data may be stored locally on the device untiltransmission for further analysis is requested. Therefore, 814 showstransmission of the data collected to a remote computing device. Asnoted above, the data may be transmitted to a location that is remotefrom the sleep study. If transmission is to occur during the study, thenthe data may be sent wirelessly via network 240 or manually downloadedvia a wire for automatic pattern analysis on the remote computing deviceat 816. As one example, the remote computing device may includeartificial intelligence for pattern matching and pattern recognitionanalysis while being configured to analyze one or more transmitted datasets. As such, a data set (e.g., images from end imaging sensor 104) canbe compared to a reference database in order to identify variouspatterns associated with sleep apnea (e.g., cross-sectional area of theimaged airway). Thereby, computing device 130 may include programmableinstructions for analyzing an image (e.g., by searching and processingarea of the airway via the binary image code data) and further comparingthe digital information to known stored patterns (e.g., imagesrepresenting AHI ) or in some instances, by comparing to the baselinedata collected when the subject is awake. Furthermore, because the datais time-stamped, the computing device may also analyze the datatemporally to arrive at a determination of sleep apnea in the manneralready described. In some embodiments, the data may be sent during thestudy but analysis may occur manually at the end of the study, forexample, after being reviewed by a trained professional that identifiespossible occurrences of airway patency. Alternatively, if transmissiondoes not occur during the study, then the data may be stored locally onthe device and downloaded at another time. At 818, collected data may bereviewed manually by a trained professional or automatically through adata processor located on the remote computing device. The dataprocessor may comprise a pattern matching algorithm with patternrecognition capabilities to identify patterns of airway obstruction anda relationship to recorded airflows, oxygen saturations, and EEG or EKGchanges. Upon conclusion of the study, at 820, a sleep study report maybe generated by the remote computing device to facilitate physiciandiagnosis of OSA based on the data recorded.

In FIG. 9, an example flow chart of method 900 illustrates a process fordiagnosing OSA based on data received from the airway assessingapparatus. As described above, the wearable device may comprise aninflatable balloon to anchor the nasal tube such that the end imagingsensor is disposed in an airway image data collection position. As such,the method for monitoring an upper airway constriction associated withOSA includes receiving airway image data from a remote end imagingsensor coupled to a nasal tube disposed within an upper airway above aconstriction point, where such airway image data was recorded during asleep period, analyzing the data received, and further displaying thedata and other pertinent information related to obstructive sleep apneain a sleep study report. In this way, the airway image data can be usedto identify airway closures related to obstructive sleep apnea.

At 902, method 900 includes receiving airway image data that istime-stamped from a remote end imaging sensor coupled to the nasal tubedisposed within an upper airway above a constriction point, where suchairway image data was recorded during a sleep period as described above.In one embodiment, method 900 includes receiving airway image data incombination with data from one or more additional sensors. For example,biophysical data may be collected from an oxygen saturation sensor andthereby represent an airway closure via a signal associated with anamount of dissolved oxygen in the body tissue. As another example,biophysical data may be additionally or alternatively collected from oneor more capnography sensors capable of determining a gas level orexchange rate within an airway during the sleep period. As yet anotherexample, data from a sound-detecting device (e.g., a microphone) may becollected that indicates an airway closure, and thereby an airflow. Inanother embodiment, method 900 may additionally or alternatively includereceiving head position data from a sensor that indicates a headposition relative to the nasal tube as described above with respect toFIG. 4. Although various examples are provided, it will be understoodthat a data set may be received that includes various combinations ofthe data collected by one or more sensors in combination with the visualimages collected by the end imaging sensor. For instance, a data setreceived may include visual images along with head position data, whichallows for a positional OSA to be determined in the manner describedabove. Alternatively, in another instance, visual images may be receivedin combination with a head position and/or an oxygen saturation level todetermine the extent of OSA during a sleep cycle. Accordingly, data fromall sensors present on the device may also be received and analyzed inthe manner described herein.

At 904, method 900 further includes analyzing the airway image data todetermine the frequency and number of airway obstructions that occurduring a sleep study. For simplicity, the method is described withrespect to the frequency and number of closures that occur. However, oneor more remote devices may also be configured to analyze the extent ofairway closure episodes and thereby determine AHI . As described above,AHI refers to the number of apnea and hypopnea episodes occurring withina time period, for instance, per hour of sleep, and the system describedobtains the AHI via a direct imaging of the airway. Alternatively, OSAanalytical toolbox 132 may include instructions for counting the numberof head movements that occur during a sleep study and so include acounter indicating the number or frequency of head movements in order todetermine the quality of sleep. Therefore, various analytical activitiesand combinations thereof may be performed to determine OSA, AHI , sleepquality, etc.

At 906, method 900 includes displaying in a sleep study report theairway image data to identify airway closures related to OSA. The sleepstudy report may include be a printout generated by a printing device(e.g., a printer) that relates to the sleep pattern data and OSA,however this is non-limiting and the sleep study report may also be adigital document that is viewed on a screen and/or securely transferred(e.g., via e-mail) to a healthcare professional, patient, etc. In thisway, the device and methods described herein can be used to advantagefor diagnosing obstructive sleep apnea, particularly in response to asleep position, and especially when sleep activities occur remotely, bydirectly imaging the airway.

The reading of the description by those skilled in the art would bringto mind many alterations and modifications without departing from thespirit and the scope of the description. It is to be understood that theconfigurations and/or approaches described herein are exemplary innature, and that these specific embodiments or examples are not to beconsidered in a limiting sense, because numerous variations arepossible. The specific routines or methods described may represent oneor more of any number of data collection strategies. As such, variousacts illustrated may be performed in the sequence illustrated, in othersequences, in parallel, or in some cases omitted. Likewise, the order ofthe above-described processes may be changed.

It will be appreciated that the configurations and routines disclosedherein are exemplary in nature, and that these specific embodiments arenot to be considered in a limiting sense, because numerous variationsare possible. The subject matter of the present disclosure includes allnovel and nonobvious combinations and subcombinations of the varioussystems and configurations, and other features, functions, and/orproperties disclosed herein.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

The invention claimed:
 1. A device for detecting airway obstructionsduring sleep to diagnose obstructive sleep apnea (OSA), comprising: awearable hollow nasal tube having a first end and second end adapted tobe positioned in an upper airway above a constriction point; an endimaging sensor at the first end of the nasal tube adapted to collectairway image data; a controller and communication interface configuredto communicatively link and relay the airway image data to a selectremote device to determine airway obstructions; a nose stopper connectedto the second end of the nasal tube adapted to stabilize the nasal tubein a select position and direct air through the nasal tube, and aninflatable balloon on the nasal tube between the end imaging sensor andthe nose stopper adapted to anchor the wearable nasal tube in the selectposition to collect the airway image data, wherein the inflatableballoon expands to a diameter greater than a diameter of the nasal tube.2. The device of claim 1, wherein the nasal tube is curved relative to alongitudinal axis.
 3. The device of claim 1, wherein the end imagingsensor is placed at a distal end of the nasal tube such that an imagedata collection position of the end imaging sensor is within anasopharynx above the constriction point, and wherein the end imagingsensor is further angled downward relative to a nose opening to view anairway.
 4. The device of claim 1, wherein the end imaging sensor is oneof a camera and a thermal imaging device.
 5. The device of claim 1,further comprising a light source to illuminate the airway for airwayimage data collection.
 6. The device of claim 1, further comprising asound-detecting sensor, wherein the sound-detecting sensor is at leastone of a microphone, a stethoscope or a Doppler sound device.
 7. Thedevice of claim 1, further comprising an oxygen saturation sensor tocollect airway data, where the airway data is relayed to a select remotedevice with the airway image data.
 8. The device of claim 1, furthercomprising a head position sensor for collecting head position datarelative to a device orientation, where the head position data isrelayed to a select remote device with the airway image data.
 9. Thedevice of claim 8, wherein the head position sensor includes one of: anaccelerometer, a gyroscope, and a sensor for detecting motion.
 10. Thedevice according to claim 6, further comprising a head movement counterto collect head position data including a number and frequency of headmovements during sleep.
 11. The device according to claim 1, furthercomprising one or more biophysical sensors comprising one or more of: anEEG sensor, an EKG sensor, and a capnography sensor capable ofdetermining a gas level or exchange rate within an airway based on datacollected.
 12. The device of claim 1, wherein the nose stopper comprisesmesh that enables air to pass through the device.
 13. The device ofclaim 1, wherein the inflatable balloon is adapted to form a seal with anasal cavity.
 14. A system for remotely diagnosing obstructive sleepapnea, comprising: a tubular airway assessing apparatus adapted to bedisposed within an upper airway, the tubular airway assessing apparatuscomprising: a wearable nasal tube having a first end and second end withan end imaging sensor at the first end for directly viewing an airway togenerate airway image data; a nose stopper at the second end adapted tostabilize the nasal tube in a select position and direct air flowthrough the first and second end of the nasal tube; an inflatableballoon on the nasal tube between the end imaging sensor and the nosestopper adapted to anchor the wearable nasal tube in the selectposition, wherein the inflatable balloon expands to a diameter greaterthan a diameter of the nasal tube; an airflow indicator configured todetermine an airway airflow to generate airflow data; a processor, acommunication interface and memory to collect and relay the airway imagedata and the airflow data over a network; a remote computing deviceconfigured to analyze breathing pattern data associated with obstructivesleep apnea; a communicative link between the tubular airway assessingapparatus and remote computing device configured to relay the airwayimage data to the remote computing device to determine airwayobstructions.
 15. The system of claim 14, wherein the airflow indicatoris a sound-detecting sensor.
 16. The system of claim 14, furthercomprising an oxygen tissue sensor.
 17. The system of claim 14, furthercomprising a head position sensor and head movement counter to determinehead position data during a sleep cycle.
 18. The system of claim 14,further comprising one or more biophysical sensors comprising: an EEGsensor, an EKG sensor, and capnography sensor for determining a gaslevel or exchange rate within an airway based on data collected.
 19. Thesystem of claim 14, wherein the remote computing device is programmed toautomatically analyze data received from the tubular airway assessingapparatus and where the airway image data is time-stamped.
 20. Thesystem of claim 14, wherein the tubular airway assessing apparatusfurther comprises an air sampling tube to sample air and airflow withina nasal cavity and/or an oral cavity.
 21. The system of claim 20,wherein the air sampling tube is coupled to the nose stopper.